1.1.33-beta5 • Public • Published

    MakerDAO Testchain

    This tool will help you set up a local testchain with all the contracts needed for the Dai.js library. These are preserved as snapshots of the complete system, and can be launched quickly on Ganache without any additional deployment or configuration.

    These scripts can also be used to update, re-deploy, add, or remove contracts from the local testing environment, and to create new snapshots of that environment for future use.

    Installation and requirements

    Requires Node.js.

    Run npm install or yarn to install Ganache. If you only want to run the testchain with an existing snapshot (without building or deploying additional contracts), that's all you need to do.

    If you want to build and deploy contracts, you will need to install Seth and Nix (yarn install-nix). You will also need to initialize and update the git submodules by running git submodule update --init --recursive (or dapp update).

    Typical usage

    If all you need to do is run the testchain with the default snapshot, simply run:

    scripts/launch -s default --fast


    yarn launch

    For a full list of contracts included in the default snapshot, you can reference the SCD and MCD address files generated from the deployment scripts.

    Building and deploying contracts

    The easy way

    The majority of users can simply run the following built-in deployment commands:

    • yarn deploy-mcd or yarn update-mcd: Builds and deploys all MCD contracts. update-mcd will also automatically overwrite the default snapshot with the new deployment. These can be run without altering SCD or auxiliary contracts.
    • yarn deploy-scd or yarn update-scd: Builds and deploys all SCD and auxiliary contracts. update-scd will also automatically overwrite the scd-only snapshot with the new deployment. If you create a new SCD snapshot, you must subsequently redeploy MCD.

    Note that, by default, these built-in commands assume you have up-to-date submodules, and they will terminate the testchain instance upon completion.

    The less easy way

    scripts/launch is the base command.

    If run with no arguments, it will start Ganache at with the chain data it finds in var/chaindata. It will run until killed with Ctrl-C.

    If var/chaindata does not exist, and the --reset-chaindata argument is not present, the default snapshot will be used to create it.


    • -s, --snapshot: Optional. This should match the name of a folder under the snapshots folder. This will be copied to var/chaindata, overwriting anything there.

    • -d, --deploy: Optional. If set, scripts/deploy will be run once Ganache is set up, to deploy contracts to the test chain.

    • --fast: Skip git submodule update and skip running dapp build for dapps that are already built. This is accomplished by setting the SKIP_BUILD_IF_ALREADY_BUILT environment variable, so the dapp build scripts must be written (or modified; see the use of sed_inplace in scripts/deploy) to support it.

    • --reset-chaindata: Start the testchain with no data.

    • -u, --skip-update: Skip the git submodule updates, but still run dapp build on the contracts.

    • -p, --port: Start Ganache on a different port.

    • --throw-revert: Have Ganache throw an exception whenever a transaction is reverted.

    • --ci: If this is set, all unrecognized arguments will be treated as a new command. This command will be run, and Ganache will exit afterward.

    Deployer account

    Some governance processes are bypassed in the testchain deployment. This gives the deployer account special priveleges within the system (such as triggering a shutdown). This account also starts with a balance of 400 MKR.

    Address: 0x16Fb96a5fa0427Af0C8F7cF1eB4870231c8154B6
    Key: 474BEB999FED1B3AF2EA048F963833C686A0FBA05F5724CB6417CF3B8EE9697E

    Creating a new snapshot

    Create a new snapshot with: ./scripts/create-snapshot $SNAPSHOT_NAME

    Update an existing snapshot with: ./scripts/create-snapshot $SNAPSHOT_NAME --force

    If you want to update the default or scd-only snapshots, you can also run yarn create-default-snapshot or yarn create-scd-snapshot

    Contract data and build output

    When the deployment scripts are run, they copy ABI files and output addresses from the deployed contracts to a file in the out/ directory. These can be copied into the source code of applications working with the testchain as you see fit.




    npm i @makerdao/testchain

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